Method of making a pallet-type container



Dec. 2, 1969 w. B. WILKINS ET AL 3,481,808

METHOD OF MAKING A PALLET-TYPE CONTAINER Original Filed Oct. 20, 1965 .4 Sheets-Sheet l Dec. 2, 1969 w. B. WILKINS ET AL 3,481,308

METHOD OF MAKING A PALLET-TYPE] CONTAINER Original Filed Oct. 20, 1965 .4 Sheets-Sheet 2 Dec. 2, 1969 w. WILKINS E AL 3,481,3(58

METHOD OF MAKING A PALLET-TYPE CONTAINER Original Filed Oct. 20, 1965 .4 Sheets-Sheet 5 M mmw M mm n V110 I W 7 2 m 0/ Wm w mm MK M? M mi u m\ I Dec. 2, 1969 w. B. WILKINS ET AL 3,481,808

METHOD OF MAKING A PALLET-TYPE CONTAINER Original Filed Oct. 20, 1965 v4 Sheets-Sheet 4 //Z "mm. 3

M 6 U 7% 9 0 Wm 5 m i WW W Y B h fly 5 a J w pi 3,481,808 METHOD OF MAKING A PALLET-TYPE CONTAINER William Burdette Wilkins, and David J. Wyrough, Roxboro, N.C., assignors to Midland-Ross Corporation, Cleveland, Ohio, a corporation of Ohio Original application Oct. 20, 1965, Ser. No. 498,380, now Patent No. 3,370,734, dated Feb. 27, 1968. Divided and this application Oct. 20, 1965, Ser. No. 498,913.

Int. Cl. B61h 81/02; B31c 13/00; 15321) 7/12 U.S. Cl. 156-189 7 Claims ABSTRACT OF THE DISCLOSURE A method of making a heavy-duty container having a side wall and a base united and arranged to provide rigid and integrated structure wherein a mandrel and the base are initially secured together, and the side walls comprising one or more skin materials and a core material are thereafter formed over the mandrel and the base by a wrapping procedure.

Containers constructed according to this invention are designed for receiving high density material, such as ore, castings, small forgings, machine shop work, and other lading of high-weight-to-volume ratio. This invention is particularly concerned with a procedure for disposing the components in an advantageous arrangement. This application is a division of application Ser. No. 498,380, filed Oct. 20, 1965, now Pat. No. 3,370,734.

In a great many factories, warehouses, shipping terminals, and other industrial facilities, a practical mode of material handling is attained through the provision of smooth floors, lift trucks, pallets and or containers of various types. Typical pallets or containers have base dimensions exemplified by the standard four feet by six feet stevedore pallet, or a box-like container used in the small forgings or castings industries having a base, e.g., two and a half by three feet. The load capacities of such pallets or containers vary up to a couple of tons or more, and the cubic capacity of the containers may vary in the order of 10 to 150 cubic feet, depending upon the industry and the goods to be handled.

An important object of this invention is to provide an open top container of composite construction providing very high strength and serviceability in relation to its weight.

Another object is to provide the container of the foregoing object in the form of what is known herein as a pallet box characterized by an upper container portion and a base portion adapted for receiving a lifting device thereunder.

It is a further object to provide the pallet boxes or containers of the foregoing objects adapted for being lifted by a crane and tilted bottom-up to effect discharge of the contents thereof.

A further object is to provide a rapid method of manufacture adaptable especially to the use of machinery in mass production techniques.

Especially, it is an object to employ continuous wrapping procedures in constructing containers of composite construction in accordance with the above written objects.

A more specific object is to utilize adhesives in such a manner as to produce containers having metal-clad side walls with the metallic surfaces along the inner and outer peripheries of the side wall exposed.

Briefly speaking, these and other objects are accomplished in the construction of a container having a side wall and a base comprising the floor of the container United States Patent 0 3,481,808 Patented Dec. 2, 1969 wherein the side wall comprises an outer skin, an inner skin and a core material therebetween, and the base comprises a frame member and a floor member secured together of which one member fits just inside the end of the side wall on the inner periphery thereof and the other member fits outside the side wall against the entire end surface thereof. The side wall comprises a material forming the skins and a material forming the core of which one is a continuous sheet extending through a series of wraps from the inner skin to the outer skin. The other material is distributed along the length of the sheet but of less length.

In one embodiment, a skin material such as metal sheet extends as one wrap forming the inner skin, then transversely through one wrap of core material, and then through at least one outer wrap to form the outer skin. The core material, preferably of wood or other low density fibrous non-metallic material, may consist of one or more wraps, each wrap having a leading end and a trailing end spaced to form a small gap through which the skin-forming material extends. Suitable adhesive material joins all interfaces of the skin and core materials.

In another embodiment, the continuous sheet of a side wall comprises the core material and extends initially from the inner surface of the side wall with the inner skin disposed as at least one complete wrap between adjacent inner wraps of the core material, the core section comprising a plurality of wraps of the core material, and the outer skin comprising at least a full wrap of the skin material disposed between outer wraps of the core material. Wraps of the sheet of core material exteriorly of the outer skin and interiorly of the inner skin are not adhered to respective adjacent skins so as to permit removal of those portions and exposure of the skins.

In furtherance of the objects, construction of the container as defined above is carried out by providing a wrapping mandrel conforming to a desired shape of the inner surface of the side wall, assembling the base and attaching it with one member thereof normally disposed inside the end of the side wall and attached to the end surface of the mandrel in flush relation with its periphery; wrapping the continuous sheet of the core or skin material, as the case may be, over the mandrel and the base member juxtaposed therewith, the wrapping being continued to include the other material for a desired disposition thereof within the wraps of the continuous sheet; applying an adhesive to all interfaces of the materials; securing that portion of the resulting side wall to the base member wrapped to the side wall by fastening means extending entirely through the side wall into the base member; and detaching the base from the mandrel and removing the container from the mandrel.

In the drawing with respect to which the invention is described below:

FIG. 1 is a perspective view of a container constructed in accordance with the invention shown suspended by cable and with a corner broken away to show the construction of its base.

FIG. 2 is a perspective view of the container base of FIG. 1 with a floor sheet element broken away to expose an underlying component.

FIG. 3 is a schematic end view of a side wall such as used in the container of FIGS. 1 and 2 with the elements thereof separated and expanded to illustrate the arrangement thereof.

FIG. 4 is a fragmentary elevation in section of a lower corn-er portion of the container shown in FIG. 1.

FIG. 5 is a fragmentary elevation in section of a top edge portion of the side wall of the container of FIG. 1.

FIG. 6 is a perspective view of a modified pallet container showing a corner section broken away to expose the construction.

FIG. 7 is a side elevation of the container of FIG. 6 in an unloading position.

FIG. 8 is a fragmentary perspective view of a side wall portion of the container of FIG. especially illustrating a cable-receiving fixture attached to the side wall.

FIG. 9 is a fragmentary elevation in section showing the relationship of the side wall and base component of the container of FIG. 6.

FIG. 10 is a plan view with a sheet portion broken away of a modified base shown also in FIGS. 11 and 12.

FIG. 11 is a longitudinal cross section of a containerwrapping mandrel and the base of FIG. 10 attached thereto.

FIG. 12 is a longitudinal cross section of the mandrel and base of FIG. 11 illustrating tab portions of the base as incorporated into the container side wall.

FIGS. 13 and 15 are schematic end views of modified side walls with the elements thereof shown expanded and separated to illustrate the arrangement thereof.

FIG. 14 is a fragmentary transverse section of a skin component of the wall illustrated in FIG. 13.

FIGS. 16 and 17 are schematic elevations, FIG. 16 being in partial cross section, illustrating apparatus used to carry out a wrapping step entailed in the manufacture of containers according to this invention.

FIG. 18 is a schematic view of a shaping and curing press and a side wall corner component contained therein.

FIG. 19 is a perspective view of side wall components including the one positioned in the press of FIG. 18.

FIG. 20 is a schematic elevation of an apparatus for subjecting a side wall to a curing operation.

FIGS. 1 to 5 illustrate one embodiment of the invention, i.e., a pallet box or container 5 shown in toto in FIG. 1.

FIGS. 2 and 3 illustrate a base 6 and a side Wall 7, respectively, which are joined as shown in FIG. 4 by fastening means such as a plurality of staples 10 and an adhesive disposed along the interface of the base and the side wall at 11.

The base 6, as shown in FIG. 2, comprises a floor member 12 having an upper metal lamina 14 and a wooden plate 15. The base further includes a frame 17 comprising, as shown, frame pieces 18, 19, 20, and 21 secured to the upper side of the floor member against the metal plate 14. Such attachment may be effected as shown in FIG. 4 by a plurality of screws 24 which extend through stringers 25 secured to the undersurface of the floor member. The stringers have the function of reinforcing the base 6, especially if the floor plate 15 consists of boards as shown, and also to space the floor member 12 above any support surface so that lifting means, such as the fork of a fork-lift truck or cables of a cablehoist, may be inserted under the floor member.

The frame 17 has an outer periphery 27 conforming to the inner periphery of the side wall 7. This outer periphery of the frame also conforms to the outer periphery 29 of a mandrel 30 of a wrapping machine 31 shown in FIG. 16. In this figure, the base 6 with the stringers 25 removed is shown attached to an end surface of the mandrel with the outer periphery of the frame 17 in flush relation with the outer periphery of the mandrel and the inner periphery of the side wall 7. The base 6 is secured to the mandrel by means such as bolts 32. The mandrel is shown as detachable from a rotor or arbor 33 to which the mandrel is secured by bolts 34. This arrangement enables the mandrel 30 and the portions of the container 5 attached thereto to be removed in assembled condition and placed, for example, in the apparatus of FIG. 20 for a curing treatment involving heating and pressure.

FIG. 3 is in the nature of a schematic cross section or end view showing components of the side wall normally joined together by an adhesive in separated condition in order to more clearly understand the structure of the side wall in its fully manufactured condition.

FIGS. 3 and 1S illustrate details of a core material, which, in a preferred form of the invention, occurs as a plurality of pre-shaped plywood panels 35 and plywood angles 36.

In the wrapping procedure described below, the plywood pieces 35 and 36 are disposed somewhat as shown in FIG. 3, between an inner metal sheet skin 37 and an outer metal skin 38. In the embodiment presently described, the inner and outer skins of the wall are formed by one continuous sheet 40 having its leading end at 41 and its trailing end at 42. This sheet is wound in such a manner as to form overlapping portions 44 and 45 of the inner skin and overlapping portions 46 and 47 of the outer skin. The score material assembles into a substantial continuous wrap, except for a gap at 48 through which extends portions 49 of the sheet 40, joining the inner skin with the outer skin.

Although inexpensive adhesives, such as the urea formaldehyde and phenol formaldehyde resins are used as the agent for bonding the constituent plies of the panels 35 and angles 36 together, an adhesive, such as an epoxy resin, having good tenacity with metal is preferred for joining the interfaces of the angles and panels with both the inner and outer skins. In the finished wall, the components of the side wall 7 are compactly joined together, as shown in FIG. 4. Epoxy resin, or other good metal-tometal adhesive joins all metal-to-metal surfaces, such as the overlapping portions of the inner skins and outer skins mentioned above.

Preferably, the rivets 51 (see FIG. 1) extend through the side wall, e.g., approximately along lines 52 and 53 of FIG. 3 to secure the termini of the sheet 40 in case of failure of the adhesive, and to better prepare the container for the rough treatment to which a container of this type is subjected. Other features of construction of the container 5 shown in FIG. 1 preferably include a preshaped channel 55 of wear-resistant material, such as metal or reinforced plastic, stapled to the upper edge of the wall 7 by staples 56. As shown in FIG. 1, the channel 55 is provided in two preshaped halves 55a and 55b.

Another optional feature of the container 5 resides in the metal strips 57a and 57b riveted to opposite sides of the container. Each strip comprises an upper loop or eye portion suitable for connecting with lifting apparatus, such as a hoist hook, so that the container may be handled easier during dumping operations. Additional hook receptacles are provided at intermediate heights along the strips 57a and 57b formed by pins, such as 58 and 59 anchored as shown with respect to strip 57a, in both strips and supported outboardly of the respective adjacent strip by another strip 61 in spaced relationship except for its bottom portion which is shown joined by rivets to the base strip 57a and the adjacent container side. To facilitate the dumping of the container, a bracket 62 providing a hookreceiving loop 63 is attached to a bottom dihedral corner of the container running transversely of the sides to which the strips 57b and 57a are attached.

FIGS. 6, 7, 8 and 9 illustrate a modified container also equipped for unloading by upturning. As shown by FIG. 9 and the broken away corner section of the container in FIG. 6, the base 6n, the been rearranged with respect to the container of FIGS. 1 to 5 to dispose the frame 17n underneath the floor member 12n whereby the usually wooden frame is not exposed within the lading receiving space of the container. The side wall 7n, similar in construction to the above described side wall 7, has its lower end portion formed around the frame 17;: and also the floor member 1211. A plurality of screws 24 tie the various components of the base together, including four tie or subfloor runners 25. The various components of the base are preferably bonded together with an adhesive in addition to any fasteners used. The side wall 7n is joined to member 1211 by staples 10 and preferably, since the wall 7n is metal clad, by an efficient metal to wood adhesive, such as one based on an epoxy resin. As shown in FIG. 9, the metal cladding 1411 of the floor member 1211 is extended as a flange portion 65 slightly above the level of the floor along the inner skin 37n of the side wall and cemented thereto with, e.g., epoxy-type adhesive. The container is thus made more serviceable and leakproof with respect to liquids. To keep the flange portion within the desired inner periphery of the side wall 7n, the man drel on which the container Sr: is formed is relieved along its end portion to which the base 6n is attached to accommodate the up-turned flange portion 65 of the metal cladding 1411 during the wrapping procedure.

FIG. 6 shows the container 5n suspended on a cable 67 extending in a U-shape pattern around the bottom of the container and connecting with hooks of a bar spreader 68. To facilitate bottom-up unloading of the container, opposite side walls of the container have attached thereto cable guides 70 at as many elevations as desired so that the cable may be inserted at the guide of proper location, depending on the height of the center of gravity of the load carried in the container, to effect unloading as shown in FIG. 7. As described in respect to an earlier embodiment, container 5n is equipped with a fixture 71 providing a loop 72 attached to a lower dihedral corner of the container to which may be attached a draw cable 73 for tilting the container.

The cable guide 70 may consist in one desired form, as a stamping with spaced, oppositely-pointing, longitudinally-coextensive hooks 74 and 75 pressed out of a base portion 76 to efiect split-eye construction. The guides 70 are secured to the outer surface of the side wall by rivets in the manner shown or other means or spot welding to an outer metallic skin.

Another embodiment of the invention directed to increasing the strength and tightness with which the base is connected to the side wall is illustrated by FIGS. 10 to 12. FIG. 10 shows in plan view a base 6s similar to the one shown in FIG. 2 except that the top sheet element 145' has flanges or tabs 65s which project beyond the periphery of the underlying floor material having its periphery at 27s. When applied to the mandrel 30, the relationship of the base 6s with the mandrel before the side wall is formed is approximately that as shown in FIG. 11. That is to say, the flanges 65s protrude beyond the periphery of the mandrel and the frame 17s. As wrapping of the side wall 7 proceeds the flanges 65s may be folded over the adjacent portion of the side wall material at almost any stage of wrapping. However, as shown in FIG. 12, the flanges 65s are folded into face-to-face engagement with the surface of the inner skin 37 which faces inwardly of the wall 7. This is preferably done in an early phase of the formation of the side wall, i.e., during or at the completion of the wrapping of the inner skin 37 before the core material is laid onto the inner skin.

The placing of the flanges 65s against the inner skin is accompanied by the application of a strong metal-tometal adhesive at the interfaces of metallic elements also to the interfaces of non-metallic and metallic elements.

FIG. 13 illustrates a side wall 7w of modified construction. Its structure is perhaps best understood by a description of its mode of manufacture. In its simplest form, the wall comprises a continuous sheet 40w extending, as the wrapping procedure is completed, from the innermost surface of the wall to the outermost surface. The wall further comprises separate sheets which may be of the same material or different materials which are placed on the wall 7w at a proper stage of wrapping to form an inner skin 37w and an outer skin 38w. The most important reason that the core material sheet 40w extends from the innermost part of the wall to the outermost part and initially covers the inner skin and the outer skin is that it functions during wrapping as a medium for shaping the inner skin and the outer skin of the wall contour. Because of the substantial tension maintained between the supply 6 roll 78 (see FIG. 17) and the mandrel 30, the skin forming sheet 79 need not be supplied to the mandrel under tension and may actually be introduced into the bite between the sheet 40w and the mandrel by hand when sheets of skin material are of such size as to be conveniently manually handled.

Usually, but not necessarily, those portions of the core material sheet 40w covering both skins along the extreme inner and outer surfaces of the wall are applied without adhesive and are removed to expose respective skin surfaces. That is to say, a portion of the sheet 40w extending from point 81 by which it is secured to the mandrel to approximately a point 82 is not covered with adhesive. A portion of the sheet 40w on the outer skin extending from point 83 to its trailing extremity 84 is also not covered with adhesive in order that those portions of the sheet will be non-adherent with respect to the skins and be easily torn away to provide the 'wall with outer and inner metallic surfaces.

An important aspect of manufacturing the side wall 7w in FIG. 13 under present technological conditions is that, in order to utilize the currently inexpensive urea or phenol formaldehyde adhesives in adhering adjacent wraps of the core material sheet 40w, it is necessary to recognize that these adhesives are not ideal for adhering a paper or paperlike core material to skins comprising a metal. Hence, the faces 85 and 86 of the skins 37w and 38w, respectively, which face inwardly of the wall toward the main body of the core material are formed prior to the wrapping procedure by a facing material such as a lamina of paper adhered by epoxy or polyester adhesive to the surface of the metallic sheet facing the core material. For example, in FIG. 14 a small section of the inner skin 37w is shown greatly enlarged. Prior to wrapping, the metallic sheet 87 is covered by a facing material 88, such as paper, adhered to the metallic sheet by an adhesive 89. Hence, when the face of skin 37w is fed into the wrapping operation, the surface of the facing sheet 88 may be coated with a relatively inexpensive adhesive, such as used in bonding adjacent wraps of the core material to adhere the facing material 88 and the attached metallic sheet 87 to an adjacent wrap of the core material.

FIG. 15 illustrates another side wall of modified construction particularly adapted for use of wooden veneer pieces 91 which are relatively thick, lightweight and porous as compared with the continuous sheet of skin material 92. The purpose of the pieces 91 is to space the successive wraps of the continuous sheet 92 in order to establish thickness of the wall and thus develop beam strength or stiffness therein. The relation of pieces 91 to the endless direction of the wall is such that the separation lines of abutting edges of the pieces do not occur in superimposition with similar lines of separation in the next adjacent laminations of core material or pieces 91. Ideal for this purpose are the pieces 91 of L-shaped cross section shown, whereby a leading edge of one piece is disposed adjacent a corner of the wall and extends around the next occuring corner of the wall to terminate in a trailing edge. In the next adjacent lamina of pieces 91, the long and the short legs of the L-shaped pieces are reversed in direction in order to dispose the adjacent abutting ends of the pieces out of superimposition with the abutting ends of the next adjacent lamina of core material, as shown in FIG. 15 For example, wrapping of the first lamina of core material would begin with its leading edge 93 and terminate in a trailing edge 94. Wrapping the next lamina of core material is commenced at a point which peripherally spaces the leading edge 95 of the second lamina from the leading edge 93 of the first lamina. This also causes sections 96 and 97 of the continuous sheet 92 to be superimposed without core material therebetween and adhered together by the adhesive used to unite all elements of the wall 7x.

The second lamina is completed in a trailing edge 98 adjacent the leading edge at 95. As described with respect to the first lamina of core material, the sheet 92 extends between the termini of the second lamina of core material to form the next successive wrap of the skin material which extends uniformly throughout the thickness of the wall 7x.

The third lamina commences with its leading edge disposed in the direction of wrapping at a point 99 peripherally spaced from the leading edge 95 of the second lamina. In this manner, many wraps of the core material and skin material may be constructed to build the complete wall to any thickness desired with substantial dispersal of abutment gaps of the pieces of plywood forming the various laminae. The continuous sheet may be constituted of paper, films or sheets of synthetic resin, metallic foils or sheets and other flexible materials capable of forming continuous sheets.

The pieces 91 may be constituted of, in addition to wood veneer of any other similarly inexpensive material having flexibility sufiicient to be bent around corners required in the wall 7x.

During the wall forming wrapping procedure, the sheet 92 may be coated on both sides with adhesive, with the exception of the outer and inner skin forming sections thereof which are coated only on the side facing the adjacent lamina of core-forming pieces 91.

FIGS. 16 and 17 illustrate machinery which is conventional in wrapping techniques, except for the use and arrangement of mandrel 30 with the arbor 33, and the container to be constructed thereon. As suggested before, in practising this invention, it is necessary to fasten the container base to the end of the cantilever-supported mandrel 30 so that the periphery of that portion of the base in abutment with the end surface of the mandrel coincides with the periphery of the mandrel.

As each of the types of containers described above comprises a continuous sheet used to constantlymaintain a bite between the sheet and the mandrel for receiving any other component of which the side walls are composed, the continuous sheet is fastened either to the base, the mandrel, or both and wrapping proceeds intermittently or continuously, as the nature of the non-continuous components of the wall permit, to assemble the side Wall and base of the container as indicated in the description above of the various types of containers.

FIGURE 17 includes supply rolls 103 and 104 of, e.g., paper, for supplying alternatively the facing material required by the skins 37w and 38 w of FIGURE 13. It will be understood that the adhesive doctor blade and roll applying devices indicated at 106, 107, 108 and 109 may be moved or otherwise made inoperative as the occasion demands at the will of the operator to achieve application of adhesive to one or the other side of the respective sheets passing thereby.

When the wrapping is completed, the container may be retained on the mandrel, and the assembly of the mandrel and the container removed from the arbor 33 by withdrawal or unfastening of such fastening means (bolts 34 is shown in FIG. 16) to permit detachment of the assembly from the arbor. Thereafter, the wall, while mounted on the mandrel, is subjected to a curing operation which necessarily includes the application of pressure to press the elements of the side wall supported by the mandrel in tightly compacted relationship and, under usual production condition, includes the application of heat.

FIGURE 20 illustrates schematically apparatus including platens 111, 112, 113, and 114 adapted for applying both heat and pressure to a four-sided container. The apparatus 115 of FIGURE 18 shows schematically a simple press which preferably includes platens which are preferably heated for shaping and curing the plywood angles 36 of which one is shown in perspective in FIG. 19. This latter figure illustrates plywood core components of the type described with respect to FIG. 3.

8 We claim: 1. The process of constructing a pallet-type container in which the steps comprise:

forming a base by assembling wood flooring, metal plate, and frame pieces together to dispose the flooring and the plate as a planate floor with the flooring covered on one side by the metal plate and the frame pieces disposed over the metal plate and fastened to the floor to unit the base and to form an end frame with its outer periphery conforming to the inner periphery of a side wall of continuous cross section; providing a mandrel of a length conforming to the height of a side wall of the container and of a periphery conforming to that of said frame; affixing the base to the end of the mandrel to dispose the outer periphery of the frame in flush relation with that of the mandrel; forming said side wall by fastening the leading end of a metal sheet to the frame, rotating the mandrel to roll thereunto one initial wrap overlapping itself, laying onto the said wrap between the time of commencing the wrap and the beginning of the second wrap a non-metallic core material so as to provide a small gap between its leading end and its trailing end while disposing the wrap of core material to permit extension therethrough of a portion of the metal sheet which overlaps said wrap thereof; then continuing rotation of the mandrel to add a second wrap of the metal sheet over the core material; concurrently with said wrapping steps, applying a metal-to-wood adhesive to all interfacial surfaces of the metal sheet and the core material; inserting fastening means through the entire thickness of the side wall into the frame to fasten the base and the side wall together; curing the adhesive to effect substantial uniting of the side wall into an integrally bonded unit; and after curing the adhesive, removing the connected base and side wall from the mandrel. 2. The method of claim 1 wherein: said wrapping steps are efifected to dispose the leading end portion and the trailing end portion of the metal sheet over portions of the core material on opposite sides of said gap; and said leading and trailing end portions are secured to the underlying sheet material by fastening means extending through the wall. 3. The process of constructing a pallet-type container in which the steps comprise:

forming a base by (1) providing a substantially planate floor member and frame pieces and fastening them together as said base to dispose the pieces along one side of the member as an end frame with its outer periphery conforming to the inner periphery of a side wall continuous cross section, (2) providing a mandrel of a length conforming to the height of the side wall of the container and of a periphery conforming to that of said frame, (3) affixing the base to the end of the mandrel to dispose said peripheries in flush relationship; forming said continuous side wall by (1) providing a material adapted for forming an outer skin and an inner skin for said wall and a material adapted for forming a core layer between said skins, one of said materials being provided as a continuous sheet, (2) aflixing said sheet to the assembly comprising a base and a mandrel, (3) rotating the mandrel to wrap thereonto said inner skin with leading and trailing ends of the inner skin in overlapping relation, (4) continuing the wrapping to dispose said core material as a substantially continuous layer over said inner skin, and (5) continuing the wrapping to dispose said outer skin in at least one full wrap with its leading end portion overlapping its trailing end portion over said core material, (6) fastening the edge portion of said side wall overlapping the base to the base substantially along its entire periphery;

applying adhesive to said materials to dispose adhesive along substantially all inner faces of the materials; and

removing the combined base and side wall from the mandrel endwise from the end surface of the mandrel.

4. The process of claim 3 comprising:

providing said sheet of said outer and inner skin material and initially wrapping the sheet about the mandrel to an extent greater than one wrap to effect overlapping of the sheet portion forming the inner skin;

then placing on the inner skin a layer of said core material of substantially greater thickness than the skin in an arrangement defining for a small gap extending transversely of the sheet;

then with said sheet connected with the supply source thereof and extending through said gap and under the core material to form said inner skin, and continuing the wrapping of the sheet to an extent greater than one wrap over the exterior surface of the core material to form the outer skin.

5. The process of claim 3 comprising:

providing said sheet of said core material and initially wrapping a first length of said skin material onto the mandrel along with said sheet;

continuing wrapping of said sheet onto said previously PHILIP DIER, Primary Examiner wrapped materials to build up a core section of said wall of predetermined thickness;

feeding a second length of skin material onto said core section as wrapping progresses from said outer skin.

6. The process of claim 5 wherein:

a final stage of wrapping is performed in the absence of an adhesive between the portion of said sheet covering the surface of the second length of skin material facing outwardly of the wall; and

said sheet portion is removed from the completely wrapped wall.

7. The process of claim 6 wherein:

an initial stage of wrapping is performed in the absence of an adhesive between a second portion of said sheet covering the surface of said inner skin which faces into the region encircled by the wall; and

said second sheet portion is removed.

References Cited UNITED STATES PATENTS 3,345,233 10/1967 Wilkins 156-189 2,884,125 4/1959 Cadillac et a1 2l743 XR 3,262,597 7/1966 Coffey.

US. Cl. X.R. 

